Revit will call this method when done using the engine. 
   Namespace:   Autodesk.Revit.DB.PointClouds  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
  Since:  2012 
Syntax
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  Namespace:   Autodesk.Revit.DB.PointClouds  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
  Since:  2012 
| C# | 
|---|
   |  
| Visual Basic | 
|---|
   |  
| Visual C++ | 
|---|
   |